Lens shifting and focusing mechanism



June 4. 1940 A. E. SCHUBERT LENS SHIFTING AND FOCUSING MECHANISM 3 Sheets-Sheet 1 Filed March 9. 1938 4 93 3 34-^d 2v 32u #2u M3 WW 2 5 5 2 N 3 6 6 2 2/J m 9 54m 7 4 22d OJO 225 $7@` H6- w3 w y m 7 l A/whf. SC/werf .June 4 1940 A. E. SCHUBERT 2,203,658

LENS SHIFTING AND FOCUSING MECHANISM Filed March 9, 1938 5 Sheets-Sheet 2 /4/v/'n E; Schubert NVEN'TOR ATTORNEYS l Cpositiomff..4

PatentedrJun'e,

i UNITED SI''TSv PATENT oI-rice LENS SBIFTING AND FOCUSING Alvin E'. schubert, what, N. Y., assigner to v liiastmanliodak Company, Rochester, corporationpflilew-.Icrsey .'littueatitn'mirnaffissa,sensing.mass

The present 1 invention relates to la andl focusing mechanism therefor. This mechanism is particularly intended for use with a view- 5 ing device of the general type'shown and` dethe magnification ofthe image -whichisfpro-A jected onto the viewing screen. A Another object `of `the invention is the pro- 20 vision'in such an apparatus of an arrangement vfor simultaneously adjusting and focusing all of the optical members of theapparatus ,relative to thelm gate.

, '-1 :A further object or the nvenunis the pm-v 25 vision of an adjustable prismwhichmaybero- 1 4tated to adjustthe :position-of the projected.

f image Von the viewing, screen.

`Still another object of. the invention is the' provision of an arrangementxfor simultaneously moving the desired projection lensinto projecting" position, andl focusing all the optical niem- 1 bers of theapparatus.

, still further object ofthe invention isthe i: provision of a lens shifting and focusingarrange- `)Lycally focuses the positioned "lenses, and is readily ment which is positive i'n itsfaction, automatifclia'ngeable to bringanotherprojection lens Vinto Yet anotherobject ofthefinvention is the prol @vision of a: single' condenser {lensfunit wh'ich is adapted to be used with a plurality of projecting lenses of different focal lengths.

f To these and" other ends, the invention resides in certain improvements and combinations ofparts, all as willbe hereinafter'more fully in the claims at the endof-the'speciflcation,

`In the drawings: 1

` Fig.' 1 is a plan' view, witnlth top of the iamp i 50 house removed. of a lensshiftingand focusing mechanism constructed in acc'ordancc withone tion of the-various parts ;f v Fig. 2 is a sideelevationview of themecha.-

embodiment1 of the inventiongshowing the relanism illustrated in Fig.. 1, with parts in section viemngapf'y paratus, and more particularly to a lens shifting l taneously focused. i

" described,` the novel features being pointed out conseilgior seaol 1 .'and'pa'rts broken away, showing the mechanism by which the"proper`projec'tion lens is moved intoposition and theoptical members are simul- Fig. 3 is an elevation view of a portion of the the mechanism taken substantially on the line ,3 1 of Fig. 2, showing the arrangement for' holding thejprojection lens mount in ladjusted position; I Fig'. 4 is `a plan View of amodied form of.

lens'shifting and focusing mechanism, showing the arrangement of the various parts;

Flg. `5 `is a side elevation vView of .a mechanism illustrated in Fig.l 4, with parts in section,

v"showing the arrangement by which allof the loptical members are focused at one time;

Fig.l 6 isa fragmentary view of a portion of rthe mechanism illustrated in Fig. 4, showing one 4arrangement for connecting the lamphouse to the lens mount;

Fig. '7 is a plan view of still another modification of alens shifting and focusing mechanism f constructed in accordance with the present `invention; i

Fig. 8 is a vertical sectional view taken substantially on the line 8 8 of Fig. 7, showing the mechanism for shifting `the prismv mount upon the movement of the lens mount tobring the proper projection lens Vinto projecting position;`

Fig. 9 is an end view of the mechanism-illusshowing the lens and prism mounts, and the Y mechanism for simu1taneously,.shifting these mounts; f

Fig, `1o is a. vertical sectional viewtakensub! stantially on the line I`I0 of Fig. "l, showing' the arrangement by which slight .adjustments of the projection lenses are secured.

.Similar reference numerals throughout the" vvarious views indicate the same parts.

The vpresent invention relatesv to a` lens shift# ing and focusing mechanism whichis primarily designed' for use in amachine or apparatus for v enlarging small areas of printed matter which have been recorded on miniature lin. 'Agmasued July 23,v 1935. This patent' shows a hous ing orcabinet the bottom-y of which forms al viewing screen, whilethe top supports the var-- ious optical 'members and light source. vReference may be had to4 this patent `for more `detailed description.

`The present" embodiment -of the. invention .compi'ises, in .'generaL'a lens mount in `which a 455 chine of this general type is shown and described 1.,] in the patent toR. S. Hopkins, #2,008,982, isy trated in Fig.` 7, as taken from `the left thereof, i Y

50 is then reflected by the mirror 22, through an Vvopening 24 onto a suitable viewing screen which able as a unit with the lens mount.

the prism, the image on the viewing screen may v plurality of projection lenses of different focal lengths are mounted. -This mount is movable toy sired lens into projecting position. v A suitableV prism is also operatively connected to and movbe turned toreading position. v Both mechanisms are mountd on the top of the cabinet, not shown, in a manner to be hereinafter more fully described.

Fig. 1 shows aplate member 01 support` II which may be secured in/ any suitable or wellknown manner to the top of the cabinet, not shown. A lamphouse I2, of any desired construction, is positioned on one side of the film gate I3 and is slidably mounted on the member II in a manner to be later described. The lamp I4 and the reflector I5 also of any well-known construction, are positioned within the lamphouse. One or more condenser lenses, generally indicated by the numeral I6, are positioned in termediate the lamp I4 and the gate I3, and on the optical axis thereof, as is well known. These condenser lenses are mounted in a suitable housing I'I which is preferably formed integral with the lamphouse I2. By means of this arrangement the lamp I4 and the lenses I6 may be moved as a unit relative to the gate I3, for reasons to be later described.

'I'he filament image of the lamp I2 is focused, by reasonof the position of the condenser lenses I6, in one of the projection lenses I9 which are mounted in bosses 20 on a disk or lense mount 2|. 'Ihese lenses I 9 are of different focal lengths, and may be selectively brought into projecting position by rotating the mount 2l, in a manner tobe later described. These lenses I9 project the f lm image onto an inclined mirror 22 mounted on a support 23 secured to the plate I I. 'Ihe image VVmay constitute the bottom of the cabinet, as

shown in the above-mentioned patent to Hipp?,A4

"kins, When, however, onlya section of the lm vimage is of interest, or greater magnification is Y. desired,a shorter focal length lensis moved into position, as shown in Fig. 2 and later described.

When the shorter focal length lens I9 is used,

only about one-fourth of the image area of the lm strip lies within the field of the projection lens.U YIn order that the entire image may be viewed, lwith thisshort focal length lens, it is necessary to move the film gate relative to and across the axis of` the -optical system so that various-portions of the iilm image may be successively brought into projecting position. This movement of the film relative to the opticalv axisl is known as scanning. Any suitable means, such as shown and ldescribed in the applicants copending application Number 167,749, led October 20, 1937, and which has become Patent No, 2,165,419, dated July 1l, 1939, may be used'for moving the-gate for the purposes of scanning. As the scanning mechanism does lnot constitute By rotating a part of the present invention, a further description is not deemed necessary.

When, however, thleentire image on the film` strip is to be viewed on the viewing screen, the longer focal length lens I9 is moved into projecting position so that the entire image area of the lm strip lies within the field of the longer focal length lens I9. Proper focus of this longer focal length lens is secured by moving it away from the gate I3, and moving the lamphouse I2l and condenser lens assembly I6 'toward the gate. These members are preferably moved as a unit, in a manner to be later described. By means of such an arrangement a single condenser lens unit may be usedwith the two projecting lenses I9 of different focal lengths.

' The lens mount 2l is mounted on one end of a shaft 25 which is positioned within a tubular member, generally indicated by the numeral 26, journalled in spaced U-shaped brackets 21 secured by screws .28 or other suitable fastening means, to the plate I I, as shown in Fig. 1. A pin 29 passes through the shaft 25 and extends intoA diametrically arranged slots 30 formed in a reduced portion 3| of the member 26 to operatively connect the shaft 25 therto. Thus by rotating the member 26, the shaft 5 and the lens mount 2I are also rotated to move the desired focal length lens I9 into projecting position. The member 26 may be operated by a knob 32, a tubular portion 33 of which overlies the end of the member 26 and is connected thereto by means of a pin 34.

After the disk 2| has been thus rotated to bring the desired projection lens I9 into operative posilens relative to the gate I3 and along the optical axis of the lamp I9 and condenser lenses I6 to A focus the projection lens, as is apparent to those in the art. The present embodiment, however, provides an arrangement whereby the rotation of the disk 2|, to bring the desired lens I 9 into position, is also utilized to move the projections lens I9 along the optical axis to thus focus the lens.

Tothis end, the right-hand bracket 21, Fig. 2, is provided with a stationary pin 35 which projects into a helical slot 36 formed on the outer periphery of the tubular member 26, as shown in Fig. 2. By means of this arrangement, the rotation of the member 26 also moves the latter longitudinally relative to the brackets 21 to shift the disk 2I along the optical axis to focus the lens i9.- The pitch of the groove 36 is such that when .the disk 2| is rotated sufficiently to bring the adjacent lens I9 into position, the disk will also be moved along the optical axis a distance equal to the difference between the focal lengths of the lenses. It is evident, therefore, that .the lens mount or disk 2l is both rotated to bring the desired lens I9 into position, and is also simul taneously shifted along the optical axis a distance equal to the difference in the focal lengths of the adjacent lenses so that the selected lens will be brought into focus.

As positive and negative films have the emulsion coating on opposite sides of the nlm base, it is apparent that if a positive film is used and the lens 19 is focused, as above described, the lens would be slightly out of 'focus if a negative ilm were subsequently used, and conversely. This difference in focus is equal to the distance between the emulsion surfaces, which is substantially equal to the film thickness. In order to adjust for this slight difference in focus, auxiliary means is preferably provided for moving 34 extends intofa peripheral groove 49 on the `9,203,358 the shaft 25 axially relative to and independent of the member 26. To this end, an auxiliary knob I6 is formed with a shank 39 which is journaled in a central opening 46 formed in the knob 92.

'Ihe shank 39 has a threaded portion 4I which projects into a recess 42 formedin the right end of the shaft 25, as viewedin Fig. 2. The outer end of this recess is threaded to receive thepor- `tion 4| so that upon rotation of the knob 66, the

shaft 25 and lens mount 2| are moved alongthe optical axls relative to the tubular member 26 to bring thelens I9 into sharp focus. 'I'he pin portion 4I to prevent relative axial movement between the portion 4I and the tubular member 26, and cooperates with the pin 29 to operatively connect the member 26 and the shaft 25. A coil spring 44 is positioned between the end lof thev source I4 and the condenser lenses I6 must also operatively connect the lamphouse to the lens be moved relative to the gate I9 a distance equal tothe difference in the focal lengths of the lenses I9 to properly focus the image of the film strip in the positioned projection lens i9., To secure this result, the lamphouse I2 maybe preferably and independently shifted; but it is preferred to mount so that when the latteris shifted along the optical axis, in a manner above described, the lamphouse is moved as a unit therewith an amount equal to the longitudinal movement ofA the lens mount. To this end, the lamphouse I 4 has secured thereto a pair of rods 46 which slide `in bearings 41 on the plate II, and have the ends thereof secured to `the depending arms 49 lof'a bracket as. This bracket is provided with a beat; 1-

` ing 5,0 through which the reduced portion -3I of the member 26 extends so that the bracket -49is supported in suspended relation by thetubular t Thebracket 49V is held inv place against a shoulder 56 on the member 26 byfmeans of a collar 52 which is` secured to the portion 3| `of the member 26 by any suitable means such, for example. as a pin 53, all as shown in Fig.4 2; Thus as the member 26 is movedlongitudina'lly by the rotation of the knob 32, the bracket-49, and herice the lamphouse I2- with it'solamp'llv`4 and also the condenser lensesA assembly I6,` are-o moved, as a unit, withthe `lens mount .2| topoperly focus the image of the illmv strip in the se--V` lected projection lens I9. 'I'he'bracketj49 formed with a pair of laterally extending arn'rsl `member 26.

544the ends of which areformedwith bosses 455 in which are seemed the ends of rods 56 the other ends of which are slidable in bearings 51 in the right `hand bracket 21, Fig. 2. Thus when the bracket 49 is moved longitudinally, the rods 56 guide the bracket 49 to maintain the latter in proper alignment, as will be apparentl from an inspection of Figs. .1 and 2.

Means is also preferably provided` to move orA lock the various members in adjusted position In the present embodiment, this lock comprises a spring member 56, of the shape best. shownjn Fig. 3, the ends 59 of which are wrapped around and secured to the rods46. This spring is pro- .ery ofth vided with a detent 69 which is arranged to snap o into one of the notches 6I formed in the periph- 'Ihe notches 6| are. so positioned that when the `desired projection lens I9 has been moved into projectingposition, the detent 60 registers with -and snaps into one of the notches 6I, to resiliently hold the lens mount 2|, as well as the other optical members, in adjusted position.

In theoriginal recording of the image on they fllm strip, the long way of the image 4may be arranged either longitudinally or transversely of the strip, depending u`pon the article being photographed, as is well known. In. order `that these diierently arranged images may be projected in an upright, or in the same position, on the viewlens mount 2|, as shown in Fig. 3.

ing screen, the present invention provides a prism 62 by which the image may be rotated to bring v the image in proper position.

This A`prism is mounted in a prism cell 63 rotatably mounted'in a central opening 64 formed in the bracket 49 y concentricwith the optical axis. 'Ihe cell63 has secured thereto a ring gear 65 which is connected to a gear 61 mounted on one' end of the lower rod 56, Fig. 1. 'I'he otherend ofthe rod 56 is provided with a nger knob 66 by which the rod 56, and hence, by reason of the gear train v65 and 61, the prism 62 may be rotated, for the reason 4 above described. As the prism 62V is mounted in the bracket 49, the prism obviously moves asa unit with the lens mount and is always spaced the same distance from the .positioned lens I9.

It is evident from the above description'. that etI the rotation of the knob 32 will rotate the lens r` mount 2| transversely ofthe optical axis to bring the desired projection lens I9 into operative posimount 2|, bracket 49 with its prism 62, the lamphouse I2 and lamp I4,'and the condenser lenses justments of the lens I9 is secured by rotatingv` the auxiliary focusing knob 39, for reasons above Y described,`while vrotation of the'knob 69 will rotion.' This rotation of the knob 32 also shifts the V -member 26, and hence moves as a unit, the lens tate the -prism 62 tobring theiimage in the cor-v rect position von the viewing screen. v ffFigs 4; 5, 'and-'G-showa modied arrangement y by which the lamphouse andthe' condenser lens assembly ,aremoved asa unit'with-the lens and prism' -mounts 1 In this embodiment, the vlamphouse,ilamp androndenserf lens assembly, may' be of: the same general arrangement as shown 4 inFigs, 1"an'd"`2, 'and therefore designated vby the `same numerals. ,Other "ccn'rresponding parts' are also.designated-by thesame numeralsasinligs.

on and supported by a pairnof cantileverrods 19 `which are secured-to supports 1I on the plate I I, and extend through'bearings-12,formed on the side of the lamphouse I4, as clearly shownin Fig.4. c v" The projection lenses yI9 of dilerent focal lengths are mounted ina lens mount 13 which is supported on a pair of rods 4Il mounted in the bifucatcd ends15 ofA a U-shapcdbracket 16.

t This bracket is provided with apar of parallel longitudinally extendingl rods 11 which are slidably supported by bearings `I8 of al bracket 19 which, in turn, is mountedon a plate 90. This plate may befa part of orseparately secured A to the plate |I`, Figs. 1 and 2. 'me bracket-1s 4thus supports 4the 'bracket -16 "and hence the vlens mount 13. One of they -rods 14, preferably theupper one, Fig. 5, is longitudinally slidable in the bracket 16 to shift the lens mount 13 transversely of the optical axis to bring the desiredprojection lens I9 into operating position. Suitable means, such as a pair of collars 14a, may be secured to the slidable rod 14 to limit the movement thereof to properly position the lenses I9. The lens mount 13 is provided with a depending pin 8| which extends into a diagonal slot 82 formed in the cross-piece 83 of a U-shaped member 84, the side arms 85 of which are suitably secured to the sides of the condenser lens housing I1, as clearly shown in Fig. 4. I

By means of this arrangement, the transverse shifting of the lens mount 13 to bring the proper 'projection lens I9 into position may be utilized to secure part of the necessary movement of the lamp I4 and condenser lens assembly I6 along the optical axis, as will be apparent from an inspection of the drawings. A pair of screws 86 extending through slots 81 in the side arms 85 of the U-shaped member 84 and into registering apertures in the plate 88 to guide the U-shaped member as it is slid along the plate 88. These screws 86 cooperate with the rods 10 to maintain the lamphouseand condenser lens assembly in proper alignment, as it is moved along the optical axis.

The lens mount 13 is then shifted along'the optical axis by means of a rod 89 which is slidable in a bearing 98 on the bracket 19, and has the end 9| thereof threaded into a hub or boss 92 `formed on the top of the bracket 16, the purpose of the threaded engagement will be later described. A spring pressed ball 93 is positioned in the bearing 98, and is arranged to be recessed in one of the grooves 94 formed in the rod 89,

as shown in Fig. 5, to hold the rod 89, and hence, the lens mount 13 in longitudinally adjusted position. The grooves 94 are spaced along the rod 89 a distance equal to the difference in the focal lengths of the two projection lenses I9, so that the ball 93 will snap into one of the grooves 94 when the mount 13 has been moved along the optical axis the proper amount to focus the transversely positioned lens I9. As lthe lens mount is connected by the U-shaped member 84 to the lamphouse, the lamp I4 and the condenser lenses I6 will obviously also move along the optical axis as a unit with the lens mount 13 when the rod 19 is slid longitudinally, 'as above described.

Thus in the embodiment shown in Figs. 4 and 5, the lamp I4 and the lenses I6 are moved in two steps. First, they are moved part of the required distance when the lens mount 13 is shifted transversely to bring the desired projection lens I9 into position. The balance of the movement is then secured when the rod 89 is shifted longitudinally tomove the lens mount along the optical axis. In the arrangement shown in Fig. 6, however, the slot 82a, in the same position as the slot 82, is parallel to the rods 14 so thatno movement of the lamp I4 and condenser lenses I6 is secured when the lens mount 13 is shifted transversely, as above described. In this latter construction,

the entire movement of the lamp and condenser l is adapted to engage with a rack 99 formed on n the rod |88 which is slidable in spaced U-shaped recesses |8I formed in the bottom of the bracket `1li. The recesses I8I may be closed by4 suitable cover plates |82 secured to the bracket 16 in any well-known manner such for example, as by screws |83, 'I'hus by moving the rod |88 transversely, the prism 62 may be rotated for the reasons pointed out above. Suitable finger knobs are provided for moving the rods 14, 89, and |88, as illustrated in Fig. 4.

Figs. 'Ito 10 show still another modication by which the lamphouse and condenser lens assembly is moved asa unit with the lens and prism mounts. The lamp, lamphouse, and condenser lens assembly may be the same as above described, and are, therefore, given the same numerals. Other corresponding parts are also similarly designated. As in Figs. 4 to 6, the

lamphouse I2 is slidable on rods 18, which are secured to the plate II or the top of the projector cabinet, and extends through bearings 12 formed on the opposite sides of the lamphouse, as shown in Fig. '7. If desired, a spring pressed ball ||8, similar to 93, may be provided in eachbearing 12 to engage spaced notches III formed in each rod 18, to hold the lamphouse I2 in adjusted position. In this embodiment, the projecting lenses I9 are mounted in lens mounts II2 and II3 which are secured to and movable with a pair of rods I|4 and II5 supported in spaced bracket II6 secured to a plate II1 fastened to or integral with plate II. The two lens mounts I|2 and II3 are connected together by a web I|8 so that the two mounts form, in effect,- a single mount which is movable as a unit with the rods ||4 and ||5. These rods are spaced apart a distance equal to the difference in the focal lengths of the two projection lenses I9. The rod |I4 is provided with a finger knob I I9 by which the two rods |I4 and I|5, and the unitary lensy mount may be moved transversely of the optical axis to bring the desired projection lens I9 into position. The rods I|4 and |I5 are provided with stop member |28 adapted to engage the brackets II6 t`o accurately position the lens I9 on the optical axis. As the rods |I4 and II5 are spaced a distance equal to the difference in the focal lengths of the lenses I9, it is apparent that when either of the lenses is moved into position it is also automatically focused.

'I'he bottom of this unitary lens mount is provided with a plate |2| on which is mounted a rack |22 with which a gear I23'is adapted to mesh. This gear is secured to the upper end'of a shaft |24 the lower end of which carries a similar gear |25 adapted to mesh with a rack |26 formed in a-slide |21 which moves in a dovetailed groove |28 formed in the plate |I1, see Figs. 8 and 9. The upper end of the shaft |24 is supported in a bracket |29, while the lower end is journaled in the plate II1, as clearly illustrated in Fig. 8. Thus when the rods I I4 and II5, and the unitary lens mount, are shifted transversely, the rack |22 engages the teeth of the gear |23 to rotate the latter. This rotation of gear |23 also'rotates the shaft |24 and the gear |25, the latter engaging and moving the rack |26 and hence the slide |21 along the plate I|1 in the direction of the optical axis. The transverse movement of the lens mount is thus translated into an axial movement of the slide |21. A suitable prism 62 and prism cell 63,

above described, are rotatably mounted in anv opening |38 in the slide |21 so that the latter constitutes a prism mount which is movable as a unit with the lens mount.

It is apparent, upon inspection of Fig. 7, that the distance between the center lines of the lenses I9 is greater than the distance between the cen-v ter lines of the rods I I4 and ||5, the latter distance being equal to the difference in focal lengths of the lenses I9. As the prism mount |21 is moved longitudinally only a distance equal to the difference in focal lengths of the lens I9, while the latter must be moved transversely the distance `between their center lines, means must obviously be provided for arresting further movement of the prism mount 21 when the latter has been moved the required distance, yet permitting the unitary lens mounts ||2 `and ||3 to be further moved to bring the desired lens |9 into projecting position. To secure this result,the rack |22 is made of such length that after the prism mount |21 has been moved the required distance, the gear |23 moves outv of engagement vwith the rack v |22, thus preventing further operation of the mount |21. The transverse movement of the lens mount may, however, be continued until the desired lens I9 is brought into position.

This movement of the prism mount |21 is utilized to correspondingly move the lamphouse I2 and condenser lens housing I1. To secure this result, these members are all operatively connected so that they will move as a unit relative to the film gate I3. This connecting means comprises, in the present embodiment, a U-shaped Vmetal strip I3I, similar to 84, which is secured to the slide |21 and the sides of the housing I1, as shown in Fig. 7. When the lamphouse has been moved the required distance the spring pressed ball drops into the registering notch |I| to maintain the members in adjusted position. Thus the lens mount and the various optical members are moved as a unit along the optical axis a distance equal to the difference in the focal lengths of the projection lenses I9.

As pointed out above, slight adjustments tothe lenses I9 are necessary to compensate for the position of the emulsions on films of different types. This adjustment may be secured, for example. by means of gears |33 mounted on the shafts l I4 and ||5, and engaging racks |34 formed in milled out recesses |35 on the top of the lens mounts ||2 and ||3, see Figs. 7, 9, and l0. Thus when the rods |I4 and ||5 are rotated the lenses I9 are moved along the optical axis to secure the desired focus. Obviously the adjustment of the individual lens may be independently secured by separately rotating the rods |I4 and IIS. It is desired, however, to so connect the rods that the rotation of one rod will also rotate the other rod the 4proper relative amount, thus focusing both lenses |9 at the same time. lens |9 may be shifted into position cessitating any further adjustment.

This connecting means comprises a gear |36 mounted on the rod I|4 and meshing with `the gear |31 mounted on-the rod |I5. As the lenses I9 are `of different focal length, the amount of axial adjustment for each lens obviously depends on its focallength, while the relative axial movement of the lenses depends upon .their difference in focal length. However, in order for the same without vnerotative movement of the rod ||4 may impart thel required relative axial movement to both lenses I9, the gear ratio of the gears |36 and |31 should be twice the difference in focal lengths of the lenses |9. ,For example, if one lens has a focal lamp house on said base, a

Then either along said axis, and means length which is twice that of the other, the gear ratio should be 1 to 4, as shown.

As pointed out above, the prism cell 63 is provided witha ring gear 65. This ring'gear is adapted, in the present embodiment, to mesh with a rack |40 formed on the bar I4| which is slidable in bearings |42 formed on the prism mount 21, as best shown in Fig. '7. Thus by moving the bar I4| in or out, the prism 62 may be rotated to properly position the image on the viewing screen, for the reasons pointed out above. A suitable finger knob |43 may be provided on the bar I4I to facilitate the movement thereof.

It is thus apparent from the above description that the present invention provides an arrangement by which one of a moved into projecting position. It is also apparent that this positioning movement of the pro,- jection lenses may also be utilized to simultaneously shift the lens mount, prism mount, light source, and the projector lenses along the optical axis an amount equal to the difference in the focal lengths of the projection lenses. Thus when the desired projection lens is moved into position, all of the various optical members will be focused relative to the'gate and to each other to insure a properly focused image on the viewing screen. Thus a single condenser lens unit may be used with a variety of projecting lenses of different focal lengths. Furthermore, the image may be rotated by means of the prism to correctly position the image on the viewing screen. While only two projection lenses have been shown in each of the above embodiments, this is by way of illustration only, as it is contemplated that any desired number of such projection lenses may be used without departing from the spirit of the invention or the scope of the appended claims.

While certain embodiments of the invention have been disclosed, it isto be understood that the inventive idea may be carried out in a number of ways. This application is, therefore, not to be limited to the precise details described, but is intended to cover all variations and modications thereof which fall within the spirit of the invention or the scope of the appended claims.

I claim:

1. In a projecting apparatus, the combination with a base,`a film gate mounted on said base,

of a lamphouse having a light source positioned` therein, a condenser lens assembly mounted on said lamphouseand on the optical axis of said light source, means for slidably supporting said disk positioned on the opposite sideof said gate from said lamp house, said disk having mounted thereon a plurality of projecting lenses of different focal lengths, means mounted on said base for both rotating said disk to bring one of said projecting lenses into alignment with said optical axis and for moving said aligned lens said lamp housing, and said assembly for independently moving said disk along said axis relative to said housing and assembly.

2. In a projecting apparatus, the combination with a base, a film gate on said base, of a lamp house slidably mounted on said base and arranged to be moved toward and away from said gate, a light source positioned within said lamp house, a condenser lens assembly` mounted on said lamp house and positioned intermediate the light source and said gate and on the optical axis thereof, a pair of spaced bearings on said base, a tubular member mounted in said bearings, a

plurality of projection lenses of different focal lengths may be selectively shaft positioned in said member and operatively connected thereto, a disk fastened t one end of said shaft, a plurality of projecting lenses of different local lengths carried by said disk, said tubular member being formed with a spiral groove, a pin on one of said bearings projecting into said groove whereby the rotation of said tubular member will also move said shaf-t and disk along said axis, a prism mount depending from and movable with said member, a prism carried by said mount, a pair of rods connecting said prism mount with said lamp house, means for rotating said tubular member to both rotate said disc to bring one of said projecting lenses into alignment with said optical axis and for simultaneously moving said disk, said prism mount, said lamp house, and said lens assembly as a unit along said optical axis relative to said gate, means for rotating said shaft independently of said tubular member to move said disk along said axis relative to said prism mount, said lamp housing, and said lens assembly, a gear train connected to said prism mount, and a knob for operating said gear train to rotate said prism on said axis.

3. In a projecting apparatus, the combination with a base, a fllm gate mounted on said base, of a lamp house slidably mounted on said base and at one side of said gate, a light source positioned within said lamp house, a condenser lens assembly mounted on and movable with said lamp l house and positioned between said lamp house and said gate and on the optical axis of said light source, a bearing positioned on said base on the opposite side of said gate, a rod movably mounted in said bearing parallel to said axis, a depending bracket carried by said rod, a second rod slidably mounted in said bracket and movable transversely of said axis, a lens mount carried by said second rod, a plurality of projecting lenses of different focal lengths carried by said lens mount, said second rod being slidable in said bracket to move said lens mount transversely of said axis to bring one of the projecting lenses into alignment therewith, a U-shaped member slidably mounted on said base and having one end thereof operatively connected to said lamp house and the other end being formed with a transverse slot, a pin depending from said lens mount and extending into said slot to operatively connect said lens mount to said lamp house and lens assembly, means for adjusting said rst mentioned rod to move said lens mount, said. lamp house, and said lens assembly as a unit along said axis and relative to said gate, and means on said bearing for maintaining said rst mentioned rod in adjusted position.

4. In a projecting apparatus, the combination with a base, a lm gate mounted on said base, of a lamp house slidably mounted on said base and at one side of said gate, a light source positioned within said lamp house, a condenser lens assembly mounted on and movable with said lamp house and positioned between said lamp house and said gate and on the optical axis of said light source, a bearing positioned on said base on the opposite side of said gate, a rod movably mounted in said bearing parallel to said axis, a dependingbracket carried by said rod, a prism mounted in said bracket and positioned on said optical axis, a second rod slidably mounted on said bracket and movable transversely of said axis, a lens mount carried by said second rod, a plurality oi.' projecting lenses of different focal lengths carried by said lens mount, said second rod being slidable in said bracket to move said lens mount transversely of said axis to bring one of the projecting lenses into alignment therewith, a vU- shaped member slidably mounted on said base and having one end thereof operatively connected to said lamp house, the other end of said U- shaped member being formed with a transverse slot, a pin depending from said lens mount and extending into said slot to operatively connect said lens mount, and said prism mount to said lamp house and lens assembly, means for adjusting said first mentioned rod to move said lens mount, said prism mount, said lamp house, and said lens assembly as a unit along said axis and relative to said gate, means on said bearing for maintaining said rst mentioned rod in adjusted position, auxiliary means for moving said lens and prism mounts, said lamp house, and lens assembly along said axis, and a rack and pinion for rotating said prism on said axis.

5. In a projecting apparatus, the combination with a base, a nlm gate mounted on said base, of a lamp house positioned on one side of said gate` and slidably mounted on said base, a light source positioned within said lamp house, a condenser lens assembly secured to and movable as a unit with said lamp house and on the optical axis of said light source, a support mounted on said base on the opposite side of said gate, spaced brackets mounted on said support, substantially parallel rods mounted in said brackets and slidable therein in a direction transversely of said axis, a lens mount secured to and movable with said rods, a plurality of projecting lenses of different focal lengths carried by said lens mount, said rods being slidable in said brackets to move said lens mount transversely of said axis to bring one of said projecting lenses into alignment therewith, said projecting lenses being spaced a distance equal to the difference in their focal length so that when moved into projection position they will be in proper position relative to said gate, and means operatively connecting said lamp house to said lens mount so that said lamp house and lens mount will be moved as a unit relative to said gate. p f

6. In a projecting apparatus, the combination with a base, a lm gate mounted on said base, of a lamp house positioned on one side of said gate and slidably mounted on said base, a light source positioned within said lamp house, a condenser lens assembly secured to and movable as a unit with said lamp house and on the optical axis of said light source, a support mounted on said base on the opposite side of said gate, spaced brackets mounted on said support, substantially parallel rods mounted in said brackets and slidable therein in a direction transversely of said axis, a lens mount secured to and movable with said rods, a plurality of projecting lenses of different focal lengths carried by said lens mount, said rods being slidable in said brackets to move said lens mount transversely of said axis to bring one of said projecting lenses into alignment therewith, said projecting lenses being spaced a distance equal to the difference in their focal length so that when moved into projection position they will be in proper position relative to said gate, a prism mount slidably mounted on said support adjacent said lens mount, means operatively connecting said lens and prism mounts so that said mounts will move as a unit, means connecting said lamp house to said prism mount so that said lamp house will move as a unit with said lens and aaoaesa 7 axis independently of said prism moimt and said maintained in focus on said 'strip positioned in lamp house. said gate.

7. In a projecting apparatus, the combination with a base. a nlm sate mounted on said base and aranged to receive and position'a nlm strip, of a light source positioned on one s ide of said gate and in alignment therewith, a condensing lens intermediate said gate and `said light source and on the optical axis of the latter, a lens mount positioned on the opposite side of said gate,` said light source said condensing lens and said lens mount being mounted on said base for movement relative to said gate and along said axis, means supported by said base for operatively connecting said lens mount to said light source and said condensing lens, a plurality of projecting lenses of different focal lengths carried by said lens mount, means for moving said lens mountrelat -tive to said base and transverselyof said axis to `tained in focus on gate. y

position one of said projecting lenses in alignment with said gate, and means for actuating said connecting means to simultaneously move said lens mount said light source and `said condensing lens along said axis and a `predetermined distance relative to said gate so as to be mainsaid strip positioned in said-i 8. In a projecting apparatus, the combination with a base, a iilm gate mounted on said baseand arranged to receive and position a lm strip, "of a light source positioned on one side of said gate and in alignment therewith, a condensing lens intermediate said gate and said light source and on i the optical axis of the latter, a lens mount positioned on the opposite side of said gate, said light source said condensing lens and said lens mount being mounted on said base `for movement relative to said gate and along said axis, meanssupported by said base for operatively .connecting said lens mount to said light source and said condensing lens', a pluralityV of projecting lenses of different focal lengths carried by said lens mount, means for moving said lens mount relative to said base and transversely of said axis to position one of said projectinglenses in alignment with said ,i focus on Vsaid strip positioned in said. gate.

9, In a projecting apparatus, the combination' with a base, a film gate'mounted onsaid base-and i arrangedtorecive andposition aliilm strip, of 'a light 'source positioned onone' side of saidgate` and'in alignmenttherewitm a condensing lens y intermediate said gate and said light source-and on theop'tical axis of the latter, a lens mount po` sitioned on the opposite side of said gate, said light'4 source said `condensing lens and said lens 4mount being mounted on said base for movement relative to said gate and along said axis, lmeans supported by said base for operatively connecting said lens mount to said light source and said con- 65 densing lens, a plurality of -projecting lenses of i 4 different focal lengths carried by said lens mount,

4mearisfor moving said lens mount relative to saidl x `base and transversely ofsaidlaxis to position one *l fof said projecting lenses'in alignment with said gate;,. and ,a single means engagingl said j mount Ito simultaneously move. said lenswmount said'light source and said condensing las aA unit 'along said 'axis and relative to said gate-s distance lequal to the difference inthe iocal lengths of adjacent projecting lenses so asl'to be 10. In a projectiu apparatus, the combination with abase, av nlm gate mounted4 on said gate and in alignment therewith, a condensing lens intermediate said gate andv said light source and on the optical axis of the latter, a lens mount i positioned on the opposite side of` said gate, said light source said condensing lens and said lens mount being mounted on said base for movement relative to said gate and along said axis, means supported by said base for operatively connecting said lens mount tosaid light source and said condensing lens, a plurality of projecting lenses of different focal lengths carried by said lens mount, means for moving said lens mount relative to said base and transversely of said axis to position one of said projecting lenses in alignment with said gate, a single means engaging said lens mount for simultaneously moving said mount said light source and said condensing lens as `a unit along said axis and relative to said gate a distance equal to the difference in `the focal lengths of adjacent projecting lenses so as to be maintained'in focusl on said strip'positioned in said gate, and auxiliary means for moving said Vmount along` said axis landrelative to `said gate.

11. In a projecting apparatus, 'the combination with a base, a film gate mounted on said base and arranged to receive and position a hlm strip, ot a of diilerent focal lengths carried by said lensy mount, means for moving said lens mount relative to said base and transversely of said axis to position one of said projecting lenses in alignment with said gate, means for simultaneously moving said lens mount, said light source and said con, densing lens as a unit along said axis and apredetermined distance relative to said gate, and means independent of said first mentioned mount moving means for moving said mount along said t Vaxis andv relative to said gate. i

l2. In a projecting apparatus, the combination with a base, a. film gate mounted on said base and s. arranged to receive and position a lm strip, of

alight source positioned on one side of lsaid gate and in alignment therewith, a condensing lens intermediate said gate and said light sourceand on the optical axis of the latter, a lens mount posiported by said base for` operatively connecting Asaid lens 'mount to said light source and said con- Adensing11en's`,.a plurality of projecting lenses of difierent focal lengths carried by said lens mount,

rneans'forV moving said lens mount relative to ,v saidg base and transversely of said axis to posi- -tiononevof-saidprojecting lenses in alignment :with said gate,- means for simultaneously moving said lens mount said light source and said condensingflens'as Aa unitalong said axis and` a pretioned means for moving said mount, said light source, and said condensing lens along said axis and relative to said gate so as to bring the strip in said gate into sharp focus.

13,. In a projecting apparatus, the combination with a base, a lm gate mounted on said base and arranged to receive and position a film strip. of alight source positioned on one side of said gate and in alignment therewith, a condensing lens intermediate said gate and said light source and on the optical axis of the latter, a lens mount positioned on the opposite side of said gate, said light source said condensing lens and said lens mount being mounted on said basefor movement relative to said gate and along said axis, means supported by said base for operatively connecting said lens mount to said light source and said condensing lens, a plurality of projecting lenses of different focal lengths carried by said lens mount, and means for moving said lens mount transversely of said axis and relative to said base to bring one of said projecting lenses into alignment with said axis and for simultaneously moving said mount said light source and said condensing lens as a unit along said axis and a predetermined distance relative to said gate so as to be maintained in focus on said strip positioned in said gate.

14. In a projecting apparatus, the combination with a base, a nlm gate mounted on said base and` arranged to receive and position a iilm strip, of a light source positioned on one side of said gate and in alignment therewith, a condensing lens intermediate said gate and said light source and on the optical axis of the latter, a lens mount positioned on the opposite side of said gate, a prism arranged adjacent said lens mount and positioned on said optical axis, said light source said condensing lens said lens mount and said prism being mounted on said base for movement relative to said gate and along said axis, means supported by said base for operatively connecting said mount to said prism said light source and said condensing lens, a plurality of projecting lenses of different focal lengths carried by said lens mount, means for moving said lens mount relative toI said base and transversely of said axis to position one of said projecting lenses in alignment with said axis, and means for simultaneously moving said lens mount, said prism, said light source, and said condensing lens along said axis and a predetermined distance relative toy said gate so as to be maintained in focus as the strip positioned in said gate.

15. In a projecting apparatus, the combination with a base, a ilm gate mounted on said base and arranged to receive and position a film strip, of a light source positioned on one side of said gate and in alignment therewith, a condensing lens intermediate said gate and said light source and on the optical axis of the latter, a lens mount positioned on the opposite side of said gate, aprism arranged adjacent said lens mount and positioned on said optical axis, said light source said condensing lens said lens mount and said prism bedetermined distance relative to said gate, and auxiliary means independent of said last men-l axis and a predetermined distance relative to said 5 gate so as to be maintained in focus onthe strip positioned in said gate, and means for turning said prism about said axis.

16. In a projecting apparatus, the combination with a base, a film gate mounted on said base 10 and arranged to receive and position a nlm strip, of a light source postioned on one side of said gate and in alignment therewith, a condensing lens intermediate said gate and said light source and on the optical axis of the latter, a lens mount 15 positioned on the opposite side of said gate, a prism mount carried by said base and positioned adjacent said lens mount, a prism ilxed in said prism mount in alignment with said optical axis, said light source said condensing lens and said mounts 20 .being mounted on said base for movement relative to said gate and along said axis, means carried by said basefor operatively connecting said lens mount to said prism mount said light source and said condensingvlens, a plurality of project- 25,

ing lenses of different focal lengths carried by said mount, means for moving said lens mount transversely of said axis to position one of said projecting lenses in alignment with said axis, a

single means supported by said base for simul- 30 taneously moving said mounts said light source and said condensing lenses as a unit along said axis and a predetermined distance relative to said gateso as to be maintained in focus on the strip positioned in said gate, and means inde- 35 pendent oi said lens mentioned means for turning said prism about said axis.

17. In a projecting apparatus, the combination with a base, a lm gate mounted on said strip and arranged to receive and position a lm strip, of a light source positioned on one sideof said gate and in alignment therewith, a condensing lens intermediate said gate and said light source and on the optical axis of the latter, a lens mount positioned on the opposite side of said gate, a prism mount carried by said base and positioned adjacent said lens mount, a prism fixed on said prism mount in alignment with said optical axis, said light source said condensing lens and said mounts beingmounted on said base for movement relative to said gate and along said axis, means carried by said base for operatively connecting said lens mount to said prism mount said light source and said condensing lens, a plurality of projecting lenses of different focal lengths carried by said mount, means for moving said lens mount transversely of saidaxis to position one of said projecting lenses in alignment with said axis, a single means supported by said base for simultaneously moving saidmounts said light source and said condensing lenses as a unit along said axis and a predetermined distance relative to said gate so as to be maintained in focus on the strip positioned in said gate, auxiliary means for moving said lens mount along said axis, a ring gear on said prism mount, and means engaging said gear to rotate said l prism on said axis.

18. In a projecting apparatus, the combination with a base, a iilm gate mounted on said base and arranged to receive and position a film strip, of a light source positioned on one side of said gate and in alignment therewith, a condensing lens intermediate said gate and said light source and on the optical axis of the latter, a lens l.

mount positioned on the opposite side of said gate, a prism mount carried by said base and positioned adjacent said lens mount, a prism iixed in said prism mount in alignment with said optical axis, said light source said condensing lens and said mounts being mounted on said base for movement relative to said gate and along said axis, means carried by said base for operatively connecting said lens mount to said prism mount said light source and said condensing lens, a plurality of projecting lenses of diilerent focal lengths carried by said lens mount, means for moving said lens mount transversely of said axis to position one of said projecting lenses in alignment with said axis, a single means supported by said base for simultaneously moving said mounts said light source and said condensing lenses as a unit along said axis and a predetermined distance relative to said gate so as to be maintained in focus on the strip positioned in said gate, means independent of said last mentioned means for simultaneously moving said mounts said light source and said condensing lens as a unit along said axis and relative to said gate a distance substantially equal to the thickness of said strip to compensate for the position of the emulsion coating thereon, a gear train operatively connected to said prism mount, and means for actuating said gear train to turn said prism about said axis.

19. In a projecting apparatus, the combination with a base, a film gate mounted on said base and arranged to receive and position a film strip, of a light source positioned on one side of said gate and in alignment therewith, a condensing lens intermediate said gate and said light source and on the optical axis of the latter, a. lens mount positioned on the opposite side of said gate, a prism mount carried by said base and positioned adjacent said lens mount, a prism xed in said prism mount in alignment with said optical axis, said light source said condensing lens and said mounts being mounted on said base for movement relative to said gate and along said axis, means carried by said base for operatively connecting said lens mount to said prism mount said light source and said condensing lens, a plurality of projecting lenses of different focal lengths carried by said lens mount, means for moving said lens mount transversely of said optical axis to bring one of said projecting lenses into alignment therewith and for simultaneously moving both of said mounts said light source and said condensing lens as a unit along said axis and a predetermined distance relative to said gate so as to be maintained in focus on the strip positioned in said gate, and means independent of said last mentioned means for moving said lens mount along said axis and relative to said prism mount said light source and said condensing lens a distance substantially equal to the thickness of said strip to compensate for the position of the emulsion coating thereon.

20. In a projecting apparatus, the combination with a base, a film gate mounted on said base and arranged to receive and position a iilm strip, of a light source positioned on one side of said gate and in alignment therewith, a condensing lens intermediate said gate and said light source and on the optical axis of the latter, a lens mount positioned on the opposite side of said gate, a prism mount carried by said base and positioned adjacent said lens mount, a prism fixed in said prism mount in alignment with said optical axis, said light source said condensing lens and said mounts being mounted on said base for movement relative to said gate and along said axis, means carried by said base for operatively connecting said lens mount to said prism mount said light source and said condensing lens, a. plurality of projecting lenses of different focal lengths carried by said lens mount, means for moving said lens mount transversely of said optical axis to bring one of said projecting lenses into alignment therewith and` for simultaneously moving both of said mounts said light source and said condensing lens as a unit along said axis and a predetermined distance relative to said gate so-as to be maintained in focus on the strip positioned in said gate, means independent of said last mentioned means for moving said lens mount along said axis and relative to said prism mount said light source and said condensing lens a distance substantially equal to the thickness of said strip to compensate for the position of the emulsion coating thereon, and means for turnini said prism about said axis.

ALVIN E. SCHUBERT. 

